"We chose the tongue to operate the system because unlike hands and feet, which are controlled by the brain through the spinal cord, the tongue is directly connected to the brain by a cranial nerve that generally escapes damage in severe spinal cord injuries or neuromuscular diseases," says Professor Maysam Ghovanloo, who helped direct the work.

"Tongue movements are also fast, accurate and do not require much thinking, concentration or effort."

Wireless communication

The movement of the magnet is detected by sensors mounted on a dental retainer and attached on the outside of the teeth. It measures the magnetic field from different angles and provides continuous real-time measurements.

These measurements are then transmitted wirelessly to a portable computer, which can be carried on the user's clothing or wheelchair.

Ghovanloo says the researchers tested the system on 12 able-bodied volunteers and now plan to test it on people with severe disabilities.

"This device could revolutionise the field of assistive technologies by helping individuals with severe disabilities, such as those with high-level spinal cord injuries, return to rich, active, independent and productive lives," Ghovanloo says.

The researchers say the computer could be programmed to recognise a unique set of specific tongue movements for each user.

"An individual could potentially train our system to recognise touching each tooth as a different command," Ghovanloo says.

They believe the device provides an advantage over switch or joystick based devices by giving the user the options of proportional, fuzzy, or adaptive control over the environment.